Food experiments. (a) Scheme of the meat spoilage experiment. (b) Setup photo with a piece of chicken breast, the electronic nose and a membrane micropump mounted on the top. (c) Response-time dependence over spoiling meat for the sensor groups with different receptor layers, relative humidity measured with a reference sensor is plotted in blue line and linked to the right axis. (d) LDA diagram of the signal growth during meat decomposition with response measurements of the target analytes considered as a training dataset and the data recorded during meat spoilage as a test dataset, each dot corresponds to 1 h interval and dot size with the arrow—to its growth direction.